How To: Reduction Gear Oil Change

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voltamps said:
GaleHawkins, how did the magnets look?

GaleHawkins said:
.....added a quart of new ATF then added 6 oz of Archoil AR9100 fluid
Archoil says to use 1.8 oz of Archoil in that much engine oil. Could be they've seen foaming with using over 3 times as much like you did. In high-RPM spinning gears, foaming can be an issue. For example, pro racers don't dare deviate from a fully formulated & tested ("track record" is everything with pit crews) oil, engine or gearbox, out of concern they spark foaming (aeration) at high speed.

Tempting to experiment with different stuff in the fluid though. You just don't know what the final result will be, as it must compete with the regular ATF fluid for surface action. I got crazy a few years back & put in some polymer esters into a differential once, just a bit. I only imagined it might make a difference, who knows?

After a year, maybe check the magnets for iron as the only real measure we have of how much Archoil or anything else might work. Even that is subject to many variables, although one use on here (was it Estomax?) had clean magnets after a few thou miles using premium Redline D6 fluid. Some evidence the premium sauce makes a difference anyway!

Keep in mind the subject is gear box fluids because the Leaf has no engine. :)

While we use Archoil AR9100 in all motors, transmissions and gear drive lines actually the AR9100 idea was posted by another Leaf owner.
 
I wonder if the additive companies are just trying to make a buck & don't actually help a fully-formulated ATF fluid in our Leaf gearboxes. Where is the proof? Taxi fleet tests maybe? Something please.

I'd recommend Redline D6 or Amsoil SS Fuel Efficient (all PAO and/or POE base enhanced) if one wanted to improve on Nissan's Matic S for better wear protection & friction reduction. Those companies work with Lubrizol or other big chemical companies like them, to produce a tested, proven product, as is, no additives needed.

GaleHawkins said:
Keep in mind the subject is gear box fluids because the Leaf has no engine. :)
That explains why the Leaf runs so quiet. ..... Archoil says to use 4 oz in a Leaf transmission. You used 6 oz. Still, maybe it wouldn't hurt, it's impossible to tell without actual real tests.

Foaming is a concern, and the way it interacts with the tribofilm on the gear and bearing surfaces from the highly engineered, fully-formulated Nissan Matic S or similar ATF fluids Nissan specs.

Here are the instructions, and we notice Archoil has separate instructions for ICE engines vs. transmissions:
https://www.oil-fuelconsultancy.nl/images/downloads/ARCHOIL-AR9100-V3-Product-Tech-Sheet-Europe1.pdf

If somebody wanted to try to improve on an ATF fluid in a Leaf gearbox, good luck with that, it would be hit or miss.

Liqui Moly's "Ceratec", which uses hexagonal boron nitrides like Archoil, but with lots of moly added too, was tested on gears, although they don't say what "Reference Oil" it was compared to (plain base oil or a real gear lube?), so impossible to tell if the Ceratec actually improved anything. It's as if they are being deceptive. ....
https://www.liqui-moly.com/en/ca/company/stay-informed/news/detail/news/dual-protection-with-cera-tec-3477-1.html
 
voltamps said:
I wonder if the additive companies are just trying to make a buck & don't actually help a fully-formulated ATF fluid in our Leaf gearboxes. Where is the proof? Taxi fleet tests maybe? Something please.

I'd recommend Redline D6 or Amsoil SS Fuel Efficient (all PAO and/or POE base enhanced) if one wanted to improve on Nissan's Matic S for better wear protection & friction reduction. Those companies work with Lubrizol or other big chemical companies like them, to produce a tested, proven product, as is, no additives needed.

GaleHawkins said:
Keep in mind the subject is gear box fluids because the Leaf has no engine. :)
That explains why the Leaf runs so quiet. ..... Archoil says to use 4 oz in a Leaf transmission. You used 6 oz. Still, maybe it wouldn't hurt, it's impossible to tell without actual real tests.

Foaming is a concern, and the way it interacts with the tribofilm on the gear and bearing surfaces from the highly engineered, fully-formulated Nissan Matic S or similar ATF fluids Nissan specs.

Here are the instructions, and we notice Archoil has separate instructions for ICE engines vs. transmissions:
https://www.oil-fuelconsultancy.nl/images/downloads/ARCHOIL-AR9100-V3-Product-Tech-Sheet-Europe1.pdf

If somebody wanted to try to improve on an ATF fluid in a Leaf gearbox, good luck with that, it would be hit or miss.

Liqui Moly's "Ceratec", which uses hexagonal boron nitrides like Archoil, but with lots of moly added too, was tested on gears, although they don't say what "Reference Oil" it was compared to (plain base oil or a real gear lube?), so impossible to tell if the Ceratec actually improved anything. It's as if they are being deceptive. ....
https://www.liqui-moly.com/en/ca/company/stay-informed/news/detail/news/dual-protection-with-cera-tec-3477-1.html

In my mind oil additives are used to meet emotional needs of the machine's owner more than anything else. :)

Tesla uses pressurized lube with an oil filter setup for some non emotional reason I expect.

At $200-$250 a gallon the the Archoil AR9100 is not cheap. It is not the additive in the ATF but the additive in the AR9100 that leaves the ATF and bonds to the gear teeth that I am going for.

I expect the $12 per gallon Marvel Mystery Oil
We used to flush out the black ATF added more life value than the AR9100 perhaps.

Let's get real and ask how many reduction gear failures occur when the ATF was never changed?

The cool thing with the 12v battery set out one can see a three plugs. Our level check plug magnet had as much if not more steel sludge than the drain plug magnet.

Going forward we will just set out the battery and see how much steel is on the ATF level check plug and clean and replace it.

The ATF was jet black after after 37K miles for some reason. Not sure that's a bad thing since most gear box lubes wind up black.
 
GaleHawkins said:
how many reduction gear failures occur when the ATF was never changed?
One. ... That we know of. ... Valdemar's gears-bearings in there start rattling around at 160k miles. Instead of replacing the thing, he could try putting in thicker GL-5 75w-85 gear oil & see if that settled it down, cheaper. It would be a good place to try dumping in some MOS2 additive too, why not, on an older unit you're trying to get 30k more miles out of.

Guessing the bearings would be the first to go, not the gears anyway.

Interesting what might break on Leafs past 120k miles or so. One article I pulled up showed an '18 Leaf 40kWH used as a taxi in the U.K. with 120k miles, utterly abused, a good long-term test example for Nissan & AESC. Battery pouch cells expanded. Might not happen if it's not charged 4 times a day with high amps.
https://insideevs.com/news/482245/nissan-leaf-repair-liquid-cooling-benefits/

GaleHawkins said:
Going forward we will just set out the battery and see how much steel is on the ATF level check plug and clean and replace it.
Cleaning off the fill plug magnet should allow it to collect more metal out of the fluid in the future. Could be an easy way to service it from now on.
 
I exchanged the ATF in my 2013 LEAF today. The car had its original oil, and is at ~ 39k miles. Gentle driving

Word to the wise: spray some WD-40 first, and come back in 5 minutes. Those bolts are on tight.

Each magnet had some black slime but did not look covered. The photos look different ;-)
The oil itself was grey-black, and really thin. If I had not read comments I would have worried about water. The most remarkable part of the exercise was draining a fair bit less than 1.5 liters. Perhaps 1.2. Since a good 1.5 quarts went in, it means either some oil was lost over the years or the original fill was too little. I didn't see any sign of oil leaking from the bolts. After the fact, I imagine that adding oil to spec level was the useful part of this job.

Here is a link to an album of photos: https://photos.app.goo.gl/tCNbfydewcZnYejF9
The black smudges on the paper towels came off the magnets
The purplish oil on the paper towel is the original oil.
Two Alu washers were sacrificed
 
SageBrush said:
The most remarkable part of the exercise was draining a fair bit less than 1.5 liters. Perhaps 1.2. Since a good 1.5 quarts went in, it means either some oil was lost over the years or the original fill was too little. I didn't see any sign of oil leaking from the bolts. After the fact, I imagine that adding oil to spec level was the useful part of this job.
It might be the factory did it, or it evaporated out the air vent tube over the last 8 years. I think it was knightmb who noticed small amounts might be escaping out the vent tube, as he was smelling it at high speeds. One or both of those things.

This gearbox probably isn't too sensitive to 1 quart or up to 1.8 quarts since it just churns on that big gear to sling it around.

I had a '15 C-Max with what I thought was low fluid from the factory on it's Prius-style fixed planetary gearset tranny. Temperature readings taken before I corrected the fluid & after did look like there was a small amount more cooling happening when full.

Technically you never need to change this fluid again. One and done.
 
voltamps said:
Technically you never need to change this fluid again. One and done.
That's my plan :D

What did you think of the old oil and grime ? About as expected ?
 
Looked like less magnet iron than most posted on here. Gears r in good shape. A heavy foot from a start is probably what makes it worse.
 
GaleHawkins said:
Going forward we will just set out the battery and see how much steel is on the ATF level check plug and clean and replace it.
I noticed the same -- the fill plug had most of the grime, and the lion's share of the metal filings. I only remember because I was expecting the opposite.

I don't expect to put enough miles on the car before EOL or sale to think about the ATF again but I'd consider it quite reasonable after one exchange to simply pull and clean the fill plug every 30k miles or so, and perhaps exchange the oil every 90k miles. I say the latter as a WAG, meant to replenish additives.
 
SageBrush said:
voltamps said:
Technically you never need to change this fluid again. One and done.
That's my plan :D

What did you think of the old oil and grime ? About as expected ?

Looks pretty normal. The residue can appear "crunchier" than it really is, as the metal fines align themselves into spiky filaments along magnetic lines of force. When cleaning the plug you can rub the residue between your fingers to see if there are any unusually large fragments hidden, or just examine the paper towels closely.
 
Because of regen the gear teeth do get wear on both sides so that may be a factor in making metal and making making th as e oil dark.

If the battery packs would last as long as the reduction gear oil the Leaf would be a home run. :)

The Archoil AR9100 use typically doubles oil change intervals because of friction reduction being a solid boundary lubricating film solution. We have engines that go months/years without being started so I like the AR9100 to prevent dry start ups before oil pressure builds.
 
Because of regen the gear teeth do get wear on both sides so that may be a factor in making metal and making making th as e oil dark.

I'm finding it hard to understand this. When the motor goes into regeneration mode, it pulls on the "transmission", right? That should result in more wear on the usually unloaded side of the teeth, and more even wear, not less - not unlike engine braking, especially with a manual transmission...unless I'm just too foggy tonight.
 
I agree it would work like engine braking, putting forces on what I call the 'back side' of the gears. I.e. the gear faces that don't touch during normal forward acceleration (although they would under rearward acceleration).

The one obvious source of unevenness on that wear is that Regen will have a lower limit to how much force is applied, compared to normal acceleration. That and not every amount of forward thrust is countered via Regen (i.e. any time the real brakes are applied).
 
The one obvious source of unevenness on that wear is that Regen will have a lower limit to how much force is applied, compared to normal acceleration. That and not every amount of forward thrust is countered via Regen (i.e. any time the real brakes are applied).

But that's also true of ICE drivetrains, especially those with automatics.
 
Yes . . . I believe the gear wear will be markedly higher on the front side of the gears on most any vehicle, with the source of propulsion (ICEV/PHEV/BEV) playing only a small part. (I wasn't trying to suggest otherwise.)

Only in the case that all accelerating force through the gearbox is 100% matched by deceleration force (like an e-pedal with 'full' Regen) could one get close to equal gear face wear. This could also be achieved by having the brakes operate 'inboard' of the gearbox, but that has several obvious downsides. And even then there'd be unevenness due to different force levels (stopping more quickly than starting, for example).
 
bobkart said:
Only in the case that all accelerating force through the gearbox is 100% matched by deceleration force (like an e-pedal with 'full' Regen) could one get close to equal gear face wear.
Leaf does just that, matching accel and decel using the motor. .... Deceleration from the motor acting as a generator is about equal to the forward-thrust accel mode.
Remember the brake pedal you operate is actually blending in motor decel (regen) with physical brake pads.
We can accelerate at about up to 1/3 G's, and decel up to 1/3 G's is handled by the motor regen. Any braking above 1/3 G's must be done with brake pads phasing in.

One-pedal driving merely shifts (re-maps) the decel regen off the first few centimeters of travel on the brake pedal on to the accelerator pedal retreat (accel pedal lift). One-pedal driving is like a speed command with your right foot, with heavy braking of course shifted back to the usual normal brake pedal when the driver needs it.
 
voltamps said:
Any braking above 1/3 G's must be done with brake pads phasing in.
It's that unevenness I'm referring to. At least in my Leaf, maximum Regen deceleration rates aren't matched to acceleration rates . . . it's only something like 40% former to latter.
 
in gen1 leafs, we get 30kw of regen and 80kw of acceleration, second gen maybe more evenly matched with the one pedal driving and bigger batteries. I have not read up on the newer leafs and what their regen rates might be.
 
Today we got our 2016 Leaf out for the first time since changing the reduction gear ATF so the Archoil AR9100 got well mixed. We drove 12.4 miles with top speed of 70 MPH with the average more 30 MPH since we have no front cap, radiation, etc. We dropped the SOC from 87% to 77%. The last charging was done 6 Nov 2020 and SOH reading was 96.08. Today 14 May 2021 after our 12.4 mile country drive SOH was down to 96.04%. l did not know parking a Leaf froze the SOH with the 12v negative battery cable disconnected.
 
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